The present invention relates to a film pack in which film units are contained and removably held, and more particularly to an improved film pack which allows withdrawing the film unit without producing scratch marks on the surface of the film unit on which an emulsion layer is formed.
Certain types of instant film units of the diffusion transfer type are generally contained in a film cassette or film pack in stacked relation and are removably held therein. Subsequent to exposure, a film unit will be withdrawn from the film pack and then the surface of the film unit on which an emulsion layer formed is brought into slidable contact with an inner surface of an exposure frame of the film pack. Especially a peel-apart type instant film unit, which comprises separate negative and positive sheets, is designed to superpose the separate sheets relative to each other after exposure for diffusion transfer processing. For this purpose, the negative sheet is turned through 180.degree. while being withdrawn. During the 180.degree. turn, the negative sheet is forced to slide against the inner surface of the exposure frame owing to the stiffness of the negative sheet, so as to produce an increased contact pressure therebetween. Therefore, there is a high risk of scratching the image area of the negative sheet.
For preventing the negative sheet from being scratched, the film packs heretofore used have been provided with projection members engageable with lateral margins of the negative sheet outside the image area of the negative sheet. However, when the negative sheet is elastically deformed as it is moved, the deformed part of the negative sheet is forced into contact with the structure of the film pack with a high contact pressure, which produces scratch marks on the negative sheet. Such scratch marks, which are often deep and wide, have considerable effect on the printed image on the positive sheet, resulting in a poor photograph.